Didn’t see it back then, just came across this on mastodon today. Sure they are competitors, given that nextcloud started as am owncloud fork, but they probably monitored ownclouds development closer than everyone else.

It depends on the country you’re in I guess. In Germany, and other countries as well I guess, you’re not liable for stuff others people post on your platform as long as you react to reports and actually remove that shit when it’s brought to your attention. You don’t have to look at your instances media folder 24/7

Yes, it’s possible. It requires some knowledge in server administration though, you can find the specifics at the Lemmy GitHub page.